Disk abrading machine



' Jan. 6, 1942.

A.N. EMMONS 2,268,863

DISK ABRADING MACHINE Filed April 28, 1939 s Sheets-Sheet 1 ATTORNEYS,

A. N. EMMONS DISK ABRADING MACHINE Jan. 6, 1942.

Filed April 28, 1939 3 Sheets-Sheet 2 INVENTOR.

Jan. 6, 1942. A. N. EMMOYNS 2,268,863

DISK ABRADING MACHINE Filed April 28, 1939 3 Sheets-Sheet 3 INVENTOR.

Patented Jan. 6, 19 42 UNITED AT-E DISK nBaAnmc ACHINE A! NI-VEmmOIIS, Nedrow, N. Y. assignor to The Porter-Cable Machine Compan I Syracuse I a corporation of New York Application April'28, 1939, Serial'No. 270,595-

8 Claims. (c1.51- -170,) j

This invention relates to abradingi'ma'chines of the disk type shown in my Patent No. 1,983,277, December 4, 1934. In general; the

present invention resides in a number of improvements on the machine disclosed in my prior patent which result in reducing the number 'of parts in the machine, the manufacturing cost thereof, and renders the machine more compact and eflicient in operation. More'in particular the improvements are directed to the suction means for gathering up the dust created by the abrading element of the machine, and to the structure and arrangement of the abrading element per se, whereby the effective cutting life of the abrading disk is materially prolonged.

The invention has as an object an abr'ading machine of the type referred to embodying a particularly powerful suction means for gathering up all of thedust created while the machine isin use and depositing the same in adust'receiving bag. 1 The invention further includes a'novel' arrangement for attaching the dust collecting. bag

to the machine, and whereby the bag" "maybe swivelled or moved relative to the machine to 1 suit the desires of the operator, arid'Iihave also provided means for yieldingly supporting and maintaining the bag in position for most efiiciently receiving the dust from 'the suction means. I The abrading element of the disk type abradi ing machine rotates at comparatively high speed, causing the abrasive disk to become heated to a considerable degree. When the machine is employed for reconditioning surfaces which have been previously varnished, painted, or otherwise :1

coated, the heat generated by theabrasive disk softens the coating on the surface being finished, and the abrasive material on thedisk becomes filled up and clogged with the coating material which immediately ends the effective cutting life cooled during the operation of the machine and whereby the effective cutting life of the disk is materially increased. v I

The invention consists in the novel features and in the combinations and constructions hereinafter setforth and claimed.

the views.

chine shown in Figure. 1.

'- In describing this invention,- reference is made to the accompanying drawings in--which like characters designate correspondingparts injall Figure'l is a top plan view of an abrading machineembodying my invention. V

. Figure 2'is a vertical sectional view of the ma- Figure' 3 is a top. plan view'of the body section of the machine. J l Figure 4 is a bottom planview of the base sec.-

tion of the machine including the abrading element guard, but with the abrading element re- The machine here shown is of the vertical type. That is, the casing of the machine is arranged vertically with the abrading element'mounted in the lowerend thereof, and with the driving'motor arranged vertically within the casing and operati'vely connected to'the'diskI,

The casing consists mainlyof a bas'esection l and abody section ill, the upperf..portion of the base I0 is formeduwith a suction'fangcompartment I2 andith e lower portion: with an 'abradin'g element'chamber 13. The body section II is detachably-.mountedxon the base as: by

, screws. Hand is divided into'a motor; compartment. arranged in the lower end of the body. section and .a fan.compartmentjl5arrangedin the upper end ofithesec'tiomthe compartments being divided by: a' pa'rtitionlt The base section isformed'with a gear. chamber l8,.the bottom wall of which is'formed, 'bya' cap l9 detachably secured to the base,.as by screws 20. v. 1 A motorll i'smounted in the motor compartment of the'bodysection with its shaft arranged vertically, and th'elower end122 thereof extending through .the'suction fancompartme'nt l2 and into the gear, Jchamber, l8. The upper end .23 of the "motor shaft extends through 'thepartition -.l6into.the :tanchaLmber' l5, and a fan 24 is mounted thereon- The top wall of: the fan chamber is formed by a cap 25 .detachably secured to the body as byscreWs'ZB. The function of the fan 24 is to "cool the motor. 2l-:by drawing air inwardly through apertures 2T over the motor, through arcuate slots 28 .in partition I6," and dispelling the" same through apertures 29 formed adjacent the top of the body section II. The motor shaft is journalled in conventional ball bearings arranged'in the partition 16 andthe top wall of the'gear'chamber l8,"'as clearly illustrated in;Figure-2.t I .1 j

; A piniongear 30 is secured tothe lower end 2| of the motor shaft .and meshes 'with'a driven gear 32 formed with integral trunnions 33, 34 which are likewise mounted in antifriction bearings arranged in the top and bottom walls of the gear chamber. The trunnion 34 extends downwardly through the cap 19 and the abrading element is detachably secured thereto. The arrangement of the gear 32 is such that a segmental cutting portion of the abrading element extends outwardly beyond the periphery of the base.

The abrading element consists of a pad 35 which is formed of yieldable material as fiber, rubber, etc., and may be provided with a metallic backing plate 36. The pad 35 is formedupon an annular member 31 which is secured to a hub.

38 as by screws 39, with the central portion of the plate 36 clamped between the annular member 31 and hub 38. The hub is threaded upon trunnion 34. The abrasive disk 40 of sandpaper, or the like, is secured centrally against the pad as by screw 4| threading into an aperture formed in the endof the trunnion 34..

Preferably, the machine includes an inverted dish-shaped abrading element guard member 42 secured to the plate I!) by screws '20 and having a depending circumferential flange 43 encircling the periphery of the abrading element. The guard 42 is arranged concentrically of the abrading element with a portion 44 extending outwardly beyond the base of the machine and covering the segmental cutting portion of the abrading element.

The dust collecting system comprises a fan 46 mounted on the lower end 22 of the motor shaft and arranged in the fan compartment l2. This compartment is provided with a central dust intake opening 41 communicating with the abrading element chamber 13:. The dust is discharged by fan 46, through an angular opening 48 extending through the side wall of the chamber and vertically. The body section H is formed with an integral dust collecting duct 51! arranged in register with the discharge opening 48 and extending vertically A coupling member 5| is rotatably mounted in the upper end of the duct 5i! and is of angular formation. The dust collecting bag 52 is secured to the coupling member 51' and is supported in vertical position by a support member of general loop formation, with the ends 53' secured in'coil spring members 54 which in turn are mounted upon studs 55 extending into apertures formed at the outer end of the coupling 5| and are secured in place as by cotter keys 56. The intermediate portion 51 of the loop engages the top of the bag 52 and supports the same in vertical position to most eiliciently receive the dust discharged by fan 46, the dust being delivered into the top of the bag and isremoved periodically by opening the bottom of the bag through the medium of the slide fastener 58. With this arrangement, the bag maybe freely swivelled to accommodate the desires of the operator, and the bag may be quickly removed. or attached to the machine by sliding the coupling member 5| into or out of the top theduct I The front side of the body section II is recessed to receive a lamp Bil, the rays of which are directed" downwardly upon the surface being finished by a guard 61 The body section is formed on opposite sides with fiat surfaces 62 to which handlesv 63 are secured for manipulating the machine. The handles 53 are secured to a plate 64 of plastic material asby screws 65, and the plate 84 is in turn secured to the body sectionas by vated from the surface being finished.

screws 66. The Plate 64 functions as an insulator to prevent heat generated in the body section by the operation of the motor from passing into the handles 63. One of the handles 63 is formed with an axially extending passage 6! to receive current carrying conductors of cable 68, and operation of the motor is controlled by a switch 69.

In operation, machines of this type are usually tilted forwardly to bring the forwardly extending segmental portion of the abrasive element into engagement with the surface bein finished,

whereby the rear portion of said element is ele- The abrasive disk 40 usually consists of a disk formed from a sheet of sandpaper and is comparatively flexible. Because of the high speed at which the abrasive element is rotated, the marginal portion of the disk tends to move outwardly from the face of the pad 35. Accordingly, there is a space 10 between the rear segmental portions of the abrasive disk and the pad. The pad, including the backing plate. 36, is formed with a plurality of circumferentially spaced apart apertures H which extend through the pad in the plate. Likewise, the guard 42 is formed with apertures 12 in the discoidal portion thereof adjacent its periphery, as indicated in Figure 4. With this arrangement, a considerable current of air is drawn in the opening 10 between the abrasive disk'and the face of the pad,'and through the apertures 1 l, I2 by the. suction fan 46. This circulation of air is also effected by the'constant movement of the marginal portion of the abrasive disk toward and from the face of the pad. That is, the forward segmental portion of the disk is pressed against the face of the pad and when this portion is rotated to the rear, it is moved away from the pad. I have found that this circulation eifectively cools the abrasive disk and the pad, with the result that the effective cutting life of the abrasive disk is at least doubled and accordingly, materially reduces the operating cost of the machine.

What I claim is: 1

1. An abrading machine comprising a base section and a body section mounted upon the upper end of said base, a motor vertically mounted in the body section with the shaft of the motor extending into the base section, an abrading disk journalled in the lower portion of the base section, gearing arranged in the base and operatively connecting said disk with the motor shaft, the upper portion of said base section being formed with a fan chamber and having a passage leading through the side wall of said chamber and extending vertically, said body section being formed with an integral vertically extending duct arranged in register with said passage in the base, a fan mounted on the motor shaft and arranged in-said fan compartment, a coupling member rotatably mounted in the upper end of said body duct, and a dust bag secured to said coupling member.

I 2. An abrading machine comprising a base section open at each end and having an enclosed gear compartment intermediate its ends, a body section mounted on the upper end of the-base, a motor mounted in the body with its shaft extending into said gear compartment,- a-n abrading element journalled in the lower end of said base section, gearing arranged in said gear compartment and operatively connecting said abrading element to said motor shaft, the upper portion ofsaid base forming a fan compartment having an intake passage opening into the lower base section, a. coupling member rotatably portion of the base to collect the dust created by said abrading element and having an angular discharge passage extending through the side wall and upper end of said base, a suction fan mounted in said fan compartment, said body section having an integral vertically extending duct arranged in register with said outlet passage in the base section, and a dust receiving bag secured to the upper end of said duct.

3. An abrading machine comprising a base section open at each end and having an enclosed gear compartment intermediate its ends, a body section mounted on the upper end of the base, a motor mounted in the body with its shaft extending into said gear compartment, an abrading element journalled in the lower end of said base section, gearing arranged in said gear compart ment and operatively connecting said abrading element to said motor shaft, the upper portion of said base forming a fan compartment having an intake passage opening into the lower portion of the base to collect the dust created by said abrading element and having an angular discharge passage extending through the side wall and upper end of said base, a suction fan mounted in said fan compartment, said body section having an integral vertically extending duct arranged in register with said outlet passage in the base section, a coupling member rotatably mounted in the upper end of said duct, and a dust receiving bag secured .to said coupling member.

4. An abrading machine comprising a base section open at each end and having an enclosed gear compartment intermediate its ends, a body section mounted on the upper end of the base, a motor mounted in the body with its shaft extending into said gear compartment, an abrading element journalled in the lower end of said base section, gearing arranged in said gear compartment and operatively connecting said abradin element to said motor shaft, the upper portion.

of said base forming a fan compartment having an intake passage opening into the lower portion of the base to collect the dust created by said abrading element and having an angular discharge passage extending through the side wall and upper end of said base, a suction fan mounted in said fan compartment, said body section having an integral vertically extending duct arranged in register with said outlet passage in the base section, a coupling member rotatably mounted in the upper end of said duct, and a dust receiving bag secured to said coupling member, and means carried by said coupling member and cooperable with the bag to yieldingly support the same.

5. An abrading machine comprising a base section open at each end and having an enclosed gear compartment intermediate its ends, a body section mounted on the upper end of the base, a motor mounted in the body with its shaft extending into said gear compartment, an abrading element journalled in the lower end of said base section, gearing arranged in said gear compartment and operatively connecting said abrading element to said motor shaft, the upper portion of said base forming a fan compartment having an intake passage opening into the lower portion of the base to collect the dust created by said abrading element and having an angular discharge passage extending through the side wall and upper end of said base, a suction fan mounted in said fan compartment, said body section having an integral vertically extending duct arranged in register with said outlet passage in the 7 5 mounted in the upper end of said duct, and a dust receiving bag secured to said coupling member, and a'bag supporting member in the form of a loop with the ends of the loop secured to said thereof.

6; An abrading machine comprising a base section open at each end and having an enclosed gear compartment intermediate its ends, a, body section mounted'on the upper end of the base, a motor mounted in the body with its shaft extending into said gear compartment, an abrading element journalled in the lower end of said base section, gearing arranged in said gear compartment and operatively connecting said abrading element to said motor shaft, the upper portion of said base forming a fanv compartment having an intake passage opening into the lower portion of the base to collect the dust created by said abrading element and having an angular discharge passage extending through the side wall and upper end of said base, a suction fan mounted in said fan compartment, said body section having an integral vertically extending duct arranged in register with said outlet passage in the base section, a coupling member rotatably mounted in the upper endof said duct, and a dust receiving bag secured to said coupling member, and a bag supporting member in the form of a loop with the ends of the loop yieldingly secured to said coupling member and the intermediate portion of the loop extending into the bag and engaging the top thereof.

7. An abrading machine comprising a body formed with an abrading element chamber, a motor mounted in the body, an abrading element journalled in said chamber and being operatively connected to the shaft of said motor, said abrading element comprising a discoidal pad formed with a plurality of circumferentially spaced apart apertures extending therethrough and a flexible abrasive sheet mounted on the face of the pad, and means operable to secure the central portion of said disk to the central portion of said pad with the marginal portion of said disk being free to move toward and from said pad, an abrasive element guard member arranged in said chamber and extending over the back of said pad in spaced apart relationship thereto and having a depending circumferential flange encircling the periphery of said pad, said guard being also formed with a plurality of circumferentially spaced apart apertures extending therethrough, suction means'arranged in the body and having anintake pas-sage extending into said chamber and being operable to draw air between the marginal portions of said abrasive disk and pad, and through the apertures of the pad and said guard.

8. An abrading machineof the type described comprising a body formed with an abrading disk chamber having an opening in one side thereof, a motor mounted in the body, an abrading disk jcurnalled in said chamber and extending outwardly through the open side thereof, whereby a segmental portion of said disk is exposed, means operatively connecting said disk to the shaft of said motor and said disk comprising a discoidal pad formed with a plurality of circumferentially spaced apart apertures extending therethrough and a flexible abrasive sheet mounted on the face of the pad, means operable to detachably secure the central portion of said disk to the central portion of said pad with the marginal portion of said disk being free to move toward and from said pad, an abrasive element guard arranged in said chamber and extending outwardly through said opening over the back of said pad and in spaced apart relation theretoand having 3, depending circumferential flange encircling the periphery of the exposed portion ARTHUR N. EMMONS. 

